The Mysterious Chest is the second novel in The Three Descendants Cycle. At the conclusion of the first book Amelia, Jake and Smoky had discovered the secret hiding place The Secret Keeper had designed to protect The Book of Legends and Prophecy's and survived Count Valadoor's ambush and traitor. This novel sees the start of The Three Descendants real journey, the journey to raise the Great Powers.
During a trip to their allies, The Gladiator's Association, Amelia, Jake and Smoky met Quintino once more, but this time they receive a message from someone that not even the first six have heard of. However this is no the only message received, Smoky hears the words of a prophecy which warns of a death of someone close to him. The message the entire group received sends them on a journey to find The Mysterious Chest whose contents promises something vital to their mission, though none actually know what is inside. There journey takes them half way across the world to the land of their allies where the find Count Valadoor lying in wait. After he leaves with the Chest in hand Amelia heads into certain death to get it back, but the choice she must make is like no other, to take the Chest, or leave it, no taking the box means killing someone she loves.

'Upon the night of the third the darkness will return. Lives will be lost, threatened will your borders be, but fear not as there will be hope. Three will come, kin of the kin of the six who will learn to control the great powers once more.'
Amelia Bravonavic is about to turn fifteen when two strange men turn up at her doorstep, one good, the other evil. However they both have something in common, they are both halfbreeds. After learning she is one herself Amelia is taken to The Royal Warriors Association, the home of her people and learns of her extraordinary powers. This links her to the one of the biggest threats the Association has ever faced. Just when Amelia doesn't think it can get any worse, she learns she is one of the only three people who can save them all.